(ITS#6890) SHA2 Password Hashing not working

Full_Name: SUDHARMA
Version: $OpenLDAP: slapd 2.4.23 (Apr 4 2011 13:48:06)
OS: AIX
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (161.134.39.30)
Hello,
we are planning to encrypt the password using SHA2 so i have followed the steps
that are required to use slapd-modules/passwd/sha2 in openLDAP code. I have
modified the slapd.conf file to load the correct libraries etc.. when i try to
generate the hash value for a password i get the following error.
testdev# slappasswd -h {SHA512}
New password:
Re-enter new password:
Password generation failed for scheme {SHA512}: scheme not recognized
I have to mention that i had problems compiling the sha2 source code with the cc
compiler but when i use the xlc i had no issues and compiled the source
successfully.
Here are the commands
xlc -I/home/openldap-2.4.23/include -g -c slapd-sha2.c
xlc -I/home/openldap-2.4.23/include -g -c sha2.c
xlc -G -I/home/openldap-2.4.23/include -g sha2.o slapd-sha2.o -o slapd-sha2.so
hope i haven't done anything wrong. Please suggest me how to make this work.
Thank you much for your help.
Best Regards,
Sudharma